Reduction of OHMIC losses in monolithic chip inductors and transformers of radio frequency integrated circuits

ABSTRACT

An inductor or transformer with the inductor can include one or more windings split into strands along a radial path of the winding and provide for a more uniform current distribution across a width of the winding. The winding(s) can comprise twisting components as twistings or strand crossings located at various locations along the winding. The twisting components span the winding along a winding width with a connector or crossing strand and change a position of one strand to another at points that different strands of the winding are cut or spliced.

RELATED APPLICATION(S)

This application is a continuation of U.S. patent application Ser. No.16/235,659, filed Dec. 28, 2018, which is incorporated by referenceherein in its entirety.

FIELD

The present disclosure relates to monolithic inductors and transformers,and more specifically, reducing ohmic losses in monolithic inductors andtransformers of radio frequency integrated circuits (RFICs).

BACKGROUND

Many monolithic inductors or transformer designs on radio frequencyintegrated circuits (RFICs) suffer from tremendous impact of radiofrequency (RF) skin and RF proximity effects, especially with respect toOhmic losses at gigahertz (GHz) frequencies. Thus, even if an inductor'sOhmic Resistance at zero frequency (DC) is fairly low, the real part(Real) of its RF impedance Z(f) can easily reach twice and triple thisvalue already at single-digit GHz frequencies, due to the adversecombination of these effects. At millimeter wave (mmWave) frequencies(e.g., at 24/28/39/60/77 GHz, higher GHz, or lower GHz) these effectscan be even more pronounced.

Partly, the ever-present problem of Ohmic losses can be mitigated byimplementation of inductors and transformers in substantially thick andhighly conductive layers of the back end of line (BEOL) stack of therespective integrated circuit (IC) technology as part of fabricationprocessing. But even in this case, still a fundamental limit ofelectromagnetic (EM) field physics prevails: RF Skin effect limits thepenetration depth into the conductor—and thus, the maximum availablecross-section for conduction of RF currents is greatly reduced, even ifa conductor is made very thick and wide. In addition to this, furtherreduction of the effective conducting cross-section area is in manycases caused by RF proximity effect, where currents in adjacent windingsinfluence each other by their surrounding magnetic fields.

A common figure of merit for inductors is the achievable Quality Factor(Q) represented as follows: Q=Imag {Z(f)}/Real{Z(f)}Eqn (1).

The Q factor is thus highly dependent on the Ohmic losses, representedby the Real part of Z(f) in the denominator. The Q factor usually isdesired to be as high as possible—at the respective operating frequencyor in a given operating frequency range. As such, equation (Eqn) 1explains the desire to lower the losses, in which the lower the losses,the higher the Q factor will be.

The magnetic fields created by the current in a current path inside theinductor cannot be assumed to be flowing equally across cross-sections(e.g., volume current distribution (Jvol)) of the current path that thecurrent is flowing equally in the cross sections. The fields can createsome bottleneck within the path such as by nearby/external/outsidemagnetic field distributions (H). Thus, there is a need to address theseissues for the sake of power efficiency/saving, fabrication processing,and efficacy of the inductor or transformer, especially with respect tonon-DC or non-changing fields at operation frequencies of RFICs.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is exemplary architecture of mobile device, or communicationequipment for an inductor component implementing various aspectsdescribed.

FIG. 2 is an example of an electromagnetic (EM) field distributionwithin inductor windings in accordance with various aspects described.

FIG. 3 is another example of an electromagnetic (EM) field distributionwithin inductor windings in accordance with various aspects described.

FIG. 4 is another example of an inductor in accordance with variousaspects described.

FIG. 5 is an example of a stranded and non-stranded winding inaccordance with various aspects described.

FIG. 6 illustrates example of an inductor in accordance with variousaspects described.

FIG. 7 is an example of a graph comparison of stranded and non-strandedwindings in accordance with various aspects described.

FIG. 8 is an example of twisting components for different strands inaccordance with various aspects described.

FIG. 9 is an example of an electromagnetic (EM) field distributionwithin inductor windings in accordance with various aspects described.

FIG. 10 illustrates another example of an inductor in accordance withvarious aspects described.

FIG. 11 illustrates an example of an inductor with a Q shield inaccordance with various aspects described.

FIG. 12 illustrates another example of an inductor with a Q shield inaccordance with various aspects described.

FIG. 13 illustrates an example of an inductor and twisting componentlocating scheme in accordance with various aspects described.

FIG. 14 illustrates another example of an inductor and twistingcomponent locating scheme in accordance with various aspects described.

FIG. 15 is a flow diagram illustrating a method of an inductor accordingto various aspects described.

FIG. 16 is another example architecture of a user (access) equipment forimplementing various aspects described.

DETAILED DESCRIPTION

The present disclosure will now be described with reference to theattached drawing figures, wherein like reference numerals are used torefer to like elements throughout, and wherein the illustratedstructures and devices are not necessarily drawn to scale. As utilizedherein, terms “component,” “system,” “interface,” and the like areintended to refer to a computer-related entity, hardware, software(e.g., in execution), and/or firmware. For example, a component can be aprocessor, a process running on a processor, a controller, an object, anexecutable, a program, a storage device, a programmable processingcircuit, a programmable array, electronic circuitry, or a computer witha processing device with circuitry. By way of illustration, anapplication running on a server and the server can also be a component.One or more components can reside within a process, and a component canbe localized on one computer and/or distributed between two or morecomputers.

Further, these components can execute from various computer readablestorage media having various data structures stored thereon such as witha module, for example. The components can communicate via local and/orremote processes such as in accordance with a signal having one or moredata packets (e.g., data from one component interacting with anothercomponent in a local system, distributed system, and/or across anetwork, such as, the Internet, a local area network, a wide areanetwork, or similar network with other systems via the signal).

As another example, a component can be an apparatus with specificfunctionality provided by mechanical parts operated by electric orelectronic circuitry, in which the electric or electronic circuitry canbe operated by a software application or a firmware application executedby one or more processors. The one or more processors can be internal orexternal to the apparatus, or operably coupled to a poweramplifier/inductor/transformer on an RF front end/Baseband side, and canexecute at least a part of the software or firmware application. As yetanother example, a component can be an apparatus that provides specificfunctionality through electronic components without mechanical parts;the electronic components can include one or more processors therein toexecute software and/or firmware that confer(s), at least in part, thefunctionality of the electronic components. As used herein, a mechanismcan be one or more components, such as a capacitor compensationmechanism/component, for example, the mechanism/component is intended todenote a structure as a mechanism or component modified by a capacitor,a compensation, or both a capacitor and a compensation, for example.

A set of elements or a set of other components can be described herein,in which the term “set” can be interpreted as “one or more.” Inaddition, use of the word exemplary is intended to present concepts in aconcrete fashion. As used in this application, the term “or” is intendedto mean an inclusive “or” rather than an exclusive “or”. That is, unlessspecified otherwise, or clear from context, “X employs A or B” isintended to mean any of the natural inclusive permutations. That is, ifX employs A; X employs B; or X employs both A and B, then “X employs Aor B” is satisfied under any of the foregoing instances. In addition,the articles “a” and “an” as used in this application and the appendedclaims should generally be construed to mean “one or more” unlessspecified otherwise or clear from context to be directed to a singularform. Furthermore, to the extent that the terms “including”, “includes”,“having”, “has”, “with”, or variants thereof are used in either thedetailed description and the claims, such terms are intended to beinclusive in a manner similar to the term “comprising”.

In consideration of the above described deficiencies, variousembodiments are described herein to fabricate and design inductors ortransformers that overcome skin and proximity effects to a greaterdegree. Inductors can be manufactured for a greater distribution ofcurrent flow throughout and within cross-sections of a winding of theinductor or electronic components comprising an inductor (e.g., atransformer or the like), thereby mitigating RF skin effects.Additionally, twisting components (or portions) with strand crossingscan be provided at various locations of an inductor winding along aradial path to reduce/mitigate RF skin effects and RF proximity effects.

In an aspect (or embodiment), an inductor component/device of a radiofrequency integrated circuit (RFIC) can include a monolithic inductorthat includes one or more inductor windings. The monolithic inductor cancomprise at least one first winding and at least one second winding, forexample. The first winding comprises a number of N strands, where N isan integer greater than one. The strands can be formed by splitting asolid inductor winding into a plurality of strands. The strands thus canbe made as individual conductors separated from one another and spacedapart (e.g., as a part of and within the inductor winding width) suchthat the solid winding now includes a plurality of conductive strandswithin the same width or space as the winding or another second winding;together the strands are configured and operable as a single inductorwinding from among two or more windings of the monolithic inductor.

In an aspect, a twisting component/device/portion/segment/mechanism canbe provided at various locations along the first winding(s), the secondwinding(s), or both first winding(s) and second winding(s) of theinductor. At respective locations along a winding of the inductor, thetwisting components can be coupled to the strands and span at least onestrand from a cut portion at a location to the position of anotherstrand at another cut portion of another strand within the location. Thetwo cuts can be proximate to and offset from one another at thelocation.

For example, within the winding the twisting component can connect afirst strand (e.g., an inner-most strand) of the plurality of strands toa second stand (e.g., an outer-most strand) of the plurality of strands,which can span across any number of strands at this location/section ofthe inductor winding. In another example, along the inductor windingpath as whole winding with the plurality of inductors, the winding cancontinue along the winding path (e.g., an angular winding path) ofconduction before joining to another winding by a windings cross(ing) orthe like to continue along another radial winding path, or be a singlewinding.

In other aspects, a transformer can comprise the monolithic inductor asa primary/secondary inductor with the twisting components at thedifferent locations of the at least one first winding. The transformercan further include a second monolithic inductor as a primary/secondaryinductor arranged with respect to the monolithic inductor and configuredto electromagnetically couple to, or mutually resonate with the othermonolithic inductor. In one example, the second monolithic inductor canbe substantially on a plane with respect to the monolithic (first)inductor, forming the transformer; other designs other than justconcentric in shape can also be envisioned, such as radially square orthe like, around a center point as one of ordinary skill in the artcould envision.

In particular, the twisting components can also be considered orreferred to as crossing(s), twisting(s), twisting scheme(s), strandcrossing(s), strand twisting(s), or other similar term or phrase herein,and is to be distinguished from and different from a “windings cross” orother similar term of art that specifies a joining of separate windingsto one another as part of the different windings of an inductor ortransformer.

As referred to herein, a winding comprises a conductive portion or oneconductive path as a portion of the inductor around a center. A windingand a strand can be distinguished by strands being in sets or groups ofstrands or conductive strips of the winding that form a singleconductive strip of a winding. Each winding can be connected to anotherwinding by a windings cross, at each strand of a set of strands of awinding to another winding (as a solid winding, or stranded winding withstrands also comprising the otherwise solid winding width). A windingcan be a conductive path or coil of an inductor that extends radially asan angular path at least three hundred and sixty degrees around a centerpoint. A half winding, for example, can include a portion of a windingsuch as about 180 degrees around a center point, for example.

Additional aspects and details of the disclosure are further describedbelow with reference to figures.

Referring to FIG. 1 , illustrated is an exemplary communication ormobile device 100 comprising an inductor component in accordance withvarious aspects being described. The device 100 can comprise a mobile orwireless device, for example, and can further include a digital basebandprocessor 102, an RF frontend 104 and an antenna port 108 for connectingto an antenna 106. The device 100 can further comprise an exemplarydriver/power amplifier 110 as a part of the digital baseband processor102 or the RF frontend 104. The digital baseband processor 102 or the RFfrontend 104 can further comprise an inductor component 112 coupled tothe power amplifier 110, the digital baseband processor 102, or the RFfrontend 104, as an external device, or integrated within or as a partof any of the devices thereof (e.g., as in an RFIC, SoC, or the like).The RF frontend 104 can also be coupled to the digital basebandprocessor 102 and the antenna port 108, which is configurable with theantenna 106.

In an example, the power amplifier 110 can operate to provide a powersignal along a transmitter path for transmissions according to variousoperating bands. The power amplifier 110 can operate in multi-band ormulti-mode operations to simultaneously support multiple communicationstandards with various operating bands. Rapidly growing demands haveposed challenges for future radio frequency (RF) transmitterdevelopment, especially power amplifiers. One solution for a multi-bandpower amplifier can be to directly assemble several single-band PAseither in a chip or on a multiple-chip module. However, this canpossibly incur large chip/module area, increased cost, a dedicatedantenna interface to each power amplifier, possibly the need foroff-chip switches or complicated packaging. Additionally, tunablepassive networks (e.g., tunable passive networks, capacitor(s),resistor(s), inductor(s), transformer(s), or the like) can also beutilized to achieve multi-band impedance matching and power combiningfor RF power amplifiers, such as with the inductor component 112 as apart of potential solutions to passive losses, tuning range options, aswell as reliability concerns, all of which can be affected by anincrease in skin effects as well as proximity field effects of theinductor.

In an aspect, the inductor component 112 can comprise one or moredevices, electric circuits, circuit components, or the likecommunicatively coupled to, connected or coupled to, integrated with oneor more inductors as inductor components 112, as well as operate atoperating frequencies in a GHz range (e.g., from one gigahertz to 99GHz, millimeter Wave (mmWave) frequencies, a half a Gigahertz, 60 Hz, 40Hz, or higher). Further, multiple inductor components 112 also can beconfigured as one or more transformers according to various details,aspects, or embodiments described herein.

In various aspects, the inductor component 112 can be configured toreduce skin effects and proximity field effects. A winding of theinductor, for example, can be modified into N strands, in which N can bean integer of at least two. The strands of a winding can be configuredto reduce or mitigate skin effects by increasing an effectivecross-section area of the winding available for conduction of radiofrequency (RF) currents in response to the radio frequency integratedcircuit operating within a frequency range (e.g., a Gigahertz frequencyrange).

The inductor component 112 can also comprising a plurality of twistingcomponents as cross strands or twisting strand at different locations ofa winding extending along a winding path (e.g., at least 360 degreeswith respect to a center point). The twisting components can beconfigured to reduce or mitigate RF proximity field effects within ororiginating from a first winding interacting with a second winding, orvice versa, as well as compared to another coil or inductor comprise ofa solid winding (e.g., a solid metal or composite winding) therein, oran inductor with all solid windings (e.g., another inductor of atransformer, or the like).

Referring to FIG. 2 , illustrated is an example of RF skin and proximityeffects that can be generated along different windings of an inductor.Specifically, five windings comprising associated cross-sectional areas202 thru 210 of each winding are illustrated as an electromagnetic (EM)field distribution Jvol (volume current). Each cross-sectional area ofeach winding 202 thru 210 demonstrates sections associated with acurrent gradient 212 thru 232, for example, that changes in currentdensity as a result of RF skin effects influencing the current flowthere-through.

As can be seen across the different current sections 212 thru 232 of thecross-sectional areas across each winding 202-210, the current is notflowing equally. The volume current (Jvol) created by the current pathinside the inductor windings cannot be assumed that to be flowingequally in the cross sections. For example, on one extreme 230-232current is only flowing at a fraction of the current density as observedon the other extreme (e.g., current sections 212 to 216). The fields ofother windings create some bottlenecks in current flow more at otherwindings, for example, especially at inner windings to the left comparedto the outer windings at the right.

Consequently, an increase in Ohmic losses over frequency due to RF skinand proximity effect can be observed. To a great extent, the dramaticloss increase on the left inner windings more so can be cause by only afew windings only, in most cases the inner and to a lesser degree theouter windings due mostly to an RF proximity effect.

Referring to FIG. 3 , illustrated is another example of RF skin andproximity effects that can be generated along different windings of aninductor, mostly illustrating the RF skin effect as a primary factoraccording to an EM field distribution.

As one example, the left winding cross-section 302 can be an inner (orinner-most) winding where different cross-sectional areas within eachcross-section 212 thru 232 demonstrate an associated current gradient,wherein 212-214 show a large flow of electrons in current as opposed tothe vast cross sectional areas of 228-232 identifying close to nothingmoving in the blue path.

In contrast to the left winding 302 cross-section, the right(outer/outer-most) winding 304 has a more uniform cross sectionalcurrent available for current, showing a greater effective cross-sectionarea of the first winding available for conduction of radio frequency(RF) currents, as such the proximity effect of the outer winding 304 tothe inner winding 304 is more pronounced, forcing the current to flowmore on a surface, and more around the regional areas 212-214 where thewinding is more conductive thereat.

Referring to FIG. 4 , illustrated is an example inductor componentaccording to various aspects herein. The inductor component 400 can beone example of the inductor component 112 of FIG. 1 as a monolithicinductor, and comprise two windings designated as a first winding 402and a second winding 410 (e.g., an outer-most winding, or other windingof the inductor where the inductor comprises more than two windings, orconfigured as part of a transformer) and a first winding 402 (e.g., aninner-most winding, or other winding of the inductor where the inductorcomprises more than two windings, or configured as part of atransformer), which are coupled to terminals 420 and 422 for receivingone or more signal inputs thereat as an electrical component that storesenergy in a magnetic field when current conducts through the windings410 and 402 as angular conductor paths. These first and second windings402 and 410 (as an inner-most winding and an outer-most winding in thegiven example of FIG. 4 ) each follow a radial path (e.g., a concentricradial winding path or other shape around a center point) and can bejoined at ends of each winding to one another at a terminal or togetherat a windings cross 408, for example.

The second winding 410 of this particular example can comprise two halfwindings as half second windings 410 a and 410 b. Each of the halfsecond windings 410 a and 410 b can be coupled to the first winding 402at end points by a windings cross 408. In this manner, the ends of thefirst winding 402 coupled to a different end of each half second winding410 a and 410 b, respectively, in which opposite ends of the half secondwindings 410 a and 410 b couple to terminals 420 and 422, respectively,by a windings cross 408 as illustrated in this particular example.

A windings cross (e.g., the windings cross 408) can be configured tocross two different windings, either at each solid winding to anotherwinding, as a solid winding to the strands of another winding, or strandto strand according to a position (e.g., inner-most strand of firstwinding to inner-most stand of second winding, and likewise for eachstrand of a winding to another winding) for example. The strands of awinding can form/comprise the same width of another winding, or at leasta same width as a solid width of the same winding in the inductor, orinclude a separate volume of strips that compose a single winding alongwith another winding also composed of a similar volume of separatestrips/strands, for example.

In an aspect, the windings 410 and 402 (as outer-most winding 410 andinner-most winding 402) of the inductor component 400 can be split intoN strands 412 _(1-N), 404 _(1-N), respectively, from a solid winding andseparated with about equal spacings (spaces/gaps) there-between withineach winding. The number of strands can vary based on a minimum width ofa solid winding (e.g., solid metal or composite of metal) based on orcontrolled by the integrated circuit (IC) fabrication processspecification(s) or technology. Although the windings 410 and 402 areboth illustrated as split into separate strands 412 _(1-N), 404 _(1-N)within each winding 410, 402 of the inductor component 400, otherconfigurations are also envisioned; such as the winding 402 being solidand the winding 410 being stranded with N strands 412 _(1-N), thewinding 402 being stranded with N strands 404 _(1-N) and the winding 410being solid, or both being stranded as illustrated, for example.

In an example, the illustration of FIG. 4 can vary so that the secondwinding 410 can be a solid metal winding without strands 412 _(1-N) orspacings (or spaces) in-between splits that run along the angular pathof the second winding 410 of the inductor 400 as otherwise illustrated.The first winding 402 can also comprise strands 404 _(1-N), so that theinductor 400 comprises the second winding 410 as a solid winding forminga solid metal second winding 410 without strands, while the firstwinding 402 can comprise strands 404 _(1-N).

The strands 404 _(1-N) of the first winding 402 can be composed of thesame metal or other composition as one another and as the solid secondwinding 410, whether the second winding 410 is entirely solid or cutinto strands 412 _(1-N), for example.

In an aspect, the second winding 410, as illustrated in the example ofFIG. 4 , comprises a number (N) of strands 412 _(1-N), which areillustrated in number as four strands within each of a half secondwinding 410 a and a half second winding 410 b. Although four strands 412_(1-N) for the second winding 410 are illustrated, the number of strands410 a and 410 b can be a different number of strands, such as two,three, four, five, or N strands with N, in which each half winding 410 aand 410 b comprises at least two strands 412 _(1-N). Similarly to thesecond winding 410 as illustrated, the first winding 402 can comprise aplurality of strands 404 _(1-N) numbering four, but also can be formedfrom more or less strands in number N, not less than two.

In an aspect, the stranded winding(s), either the first winding 402alone, the second winding 410, or both can be configured with narrowparallel strands within each winding path around a center point andenable an increased utilization of the available geometricalcross-section per winding, with respect to the RF skin and proximityeffect issues. As such, a more even current flow distribution can beconfigured by the stranded winding, especially the first winding 402,across a cross-sectional area; without which, currents of the innerwinding specifically can get pushed to just one surface (e.g., an innersurface towards the center side) with the remaining material beingbottlenecked or having very little current flow. Thus, a plurality of Nstrands making-up/forming a winding configured in the inductor 400 canincrease an effective cross-section area of the winding available forconduction of radio frequency (RF) currents, in response to the RFICoperating at an operating frequency rand (e.g., a Gigahertz range).

Briefly referring to FIG. 5 , illustrated is an example cross-section500 of a winding as a solid winding 402 (e.g., solid metal/composite)and the winding 402 with strands 404 ₁₋₄ according to various aspectsherein. As part of a IC fabrication process, the solid winding 402 canbe split into strands and spaced within the same width as the solidwinding 402 on the left.

Despite whether the first winding 402 (or the second winding 410)comprises 2, 3, 4 or more strands, the width can be a same width of agiven winding (e.g., 410 or 402) after being split into strands, so thateach winding with strands is formed into strips with a minimum volume(or width) each, and then configured to fill the volume or width of thegiven winding with any number of a plurality of strands 404 _(1-N), forexample, as in the case of winding 402. The same can be true for thewinding 410 as well. The strands 404 _(1-N) are grouped and configuredas a single winding 402, for example, that can connect to anotherwinding (either as solid metal or another group of stripped conductorstrands) as a group by the windings cross 408.

The cross-section 500 available for conduction of RF currents (I, andI/4) is marked in a hatched style in the hatched volume 502 of the solidwinding 402, for example, and the hatched volumes 504-510 of the strands404 ₁₋₄ of the stranded winding 402. The width of each strand 404 ₁ thru404 ₄ can be set or configured to be close to the admissible ‘minimumwidth’ value of the utilized IC technology, and the spacing 512 betweeneach of the strands can be set to or configured with a respective‘minimum spacing’.

The conductor height of each winding 410 and 402 can be unchanged withrespect to one another, as well as of any associated strands 412 _(1-N)or 404 _(1-N) being formed or split therein. In particular, the totalwidth (maximum extension) of the bundle of strands 404 ₁ thru 404 ₄ onthe right side can equal the width of the solid massive conductor 410 onthe left side, with a similar current being provided at each solidwinding 402 on the left and stranded winding 402 on the right. However,the stranded winding 402 on the right can induce an increase in aneffective cross-section area of the first winding available forconduction of radio frequency (RF) currents in comparison to the solidright winding 402.

The centers of a winding 402 can be prone in general to increase in skineffect and can suffer more from a bottleneck in current flow, especiallyso with the solid winding 402. The strands 404 ₁ thru 404 ₄ on thestranded winding 402 to the right are configured to increase theavailable cross areas 504-510 for conduction of RF currents much morethan the solid left winding 402. Thus, an existing inductor ortransformer design can be revamped with such strands 412 _(1-N) or 404_(1-N) (or 504-510) for lowered Ohmic losses, without having to changebasic properties like total inductor area, number of turns, orinductance value.

In an aspect, for a selective revamping process—not all windings have tobe split into N strands, some could be left unchanged and stay inmassive (sold) shape as in the example 502 as discussed above. In caseof a monolithic transformer, the coupling factor could essentially alsostay unchanged.

An estimation for N strands can be given by the followingrepresentation: Original massive winding width=N*‘min width’+(N−1)*‘minspacing’, Eqn (2), where N can be an integer from the set {2, 3, 4, 5,6, . . . }.

A reason to choose a single strand's width very close to a ‘minimumwidth’ value of the IC Technology is that for most cases of interest,the RF skin depth value can be much less than the geometrical (massive)winding width value as one solid winding. The more the conductor widthapproaches the skin depth or an even smaller value, the less pronouncedand detrimental the RF skin effect will be. This means, that even ifthis above technology-dependent choice of strand width is not optimum ina strict sense, the stranded winding at least significantly increasesthe effective conducting cross-section area compared to the winding 402being one solid winding. This can also be the same with the winding 410to some degree. Although, an example of an inner winding 402 beingnon-stranded has not been described, this does not exclude thispossibility or option, and is also envisioned as an embodiment herein.

Referring back to FIG. 4 , the inductor 400 can further comprise anumber of twisting components 414 and 406. Along a winding with a fullwinding angle of 360 degrees, the number of twists or twistingcomponents along the angular winding path can be represented by Eqn (3)as follows: A meaningful minimum number of twists (twistings/twistingcomponents, etc.)=N−1, where N=number of strands in Eqn (3). Forexample, the first winding 402 can comprise three twisting components406.

However, there could be case(s) at substantially high frequencies wherea multiple of this number of twists could be utilized, such as bydoubling, tripling, or other factor of the number of twistings. Forexample, in a case of N=4, three twistings/twisting components for thewinding (half, full or partial) could be the minimum; alternatively,six, nine, twelve, or other integer/multiple of N could be utilized.This can be applied for a full winding (360 degrees in path), a halfwinding (180 degrees in path), or an arbitrary angular winding sectionthat is less than a full winding (or winding). A trade-off can be madehowever by an increase in DC resistance value with each additionaltwisting component and an increase in volume current distribution or aneffective cross-section area of the winding available for conduction ofradio frequency (RF) currents.

In an aspect, the stranded outer-most winding 410 can comprise a numberof twisting components at each half outer-most winding 410 a and 410 bthat is equal to one less than the number of strands N for 180 degrees.

In one example, the inductor 400 can comprise a 0.6 nH inductor, with anoperating frequency of 4 GHz, and Q being equal to 16.6. This can be anincreased Q from about 14.7 without the stranded windings and thetwisting components 414 and 406, respectively. The inner winding 402 andouter winding 410 can each comprise four strands each with a 1.8micrometer width, “thick” copper utilized. In order to preserve theoriginal winding width (e.g., as shown in the winding 410 of FIG. 3 )without strands of about 10 micrometers, N=4 strands are utilized.

The twisting components 406, 414 can be configured to further reduceproximity field effects at the windings, and even more so with an innerwinding being affected by an outer winding, for example.

In an aspect, the twisting components 406, 414 can be provided toconnect to the strands of a winding at different locations along theangular winding path, and span across the strands at each location, asthe group of strands (e.g., 404 _(1-N)) with or within intermediatestrands between the outer-most strand and the inner-most strand. Thetwisting components 406, 414 are configured to slice or splice a firststrand and another second strand at the location it is coupled to andjoin these strands together at each slicing or splicing by aconnector/joining path, which is further detailed below at FIG. 6 , forexample.

Referring to FIG. 6 , illustrated is another example inductor 600similar to the inductor 400 according to various aspects furtherdetailing twisting components 404, 416.

Here, each twisting components 414 or 406 can include a strand cross orstrip path 602 joining one strand within a winding to another strand.The bottom-most twisting component 406 of the first winding 402 isdetailed to exemplify the other structures and configurations of theother twisting components as well that are located radially along anangular path of each winding 410 and 406, which are substantiallyparallel and radially-symmetric with respect to one another as in FIG. 4also.

Each twisting component 406 (as well as 414) can comprise a strand pathor connecting strip 602 that joins a strand (e.g., an inner-most strand)at a connection 604 at a cut or splicing of the strand position andextends it to another strand (e.g., an outer-most strand) at aconnection 606 as another spliced position or location thereat. Thetwisting components 414 or 406, in one example, can twist an inner-moststrand of the plurality of strands to a position 606 of an outer-moststrand of the plurality of strands along the first winding or theouter-most strand to a position 602 of the inner-most strand.

Additionally or alternatively, twisting components 414 or 406 can adjustanother path of one or more intermediate strand that is between theouter-most strand and the inner-most strand toward a center path of thefirst winding.

Although the number of strands N can be two for a particular winding, inthe illustrated example of FIG. 6 each twisting component 414 or 406 canthus span the strands 404, as well as over any intermediately locatedstrands (e.g., 404 ₂-404 ₃) there-between in order to alter thepositions of the inner- and outer-most strands at positions 604 and 606,so that the outer-most strand is positioned as an intermediate strand,and the inner-most strand at 604 becomes an outer-most strand at 606 byposition, for example.

In an aspect, the twisting component(s) 414 or 406 can be located atdifferent locations along the angular path of each winding 410 or 402based on the number of twisting components (e.g., see, Eqn. 3). Althoughthe locations of the twisting components along each winding areillustrated symmetrically with respect to a same angle difference alongthe winding angular path radially, the twisting components can also beasymmetrically distributed with respect to one another.

As discussed above, the twisting components 406, 414 can be configuredto reduce skin and proximity field effects within the inductor 400, orotherwise.

Referring to FIG. 7 , illustrated is an example graph 700 of the impactof RF skin and proximity effect in solid or massive winding shapecompared to a winding that is stranded with N strands and N−1 twistingcomponents in accordance with various aspects.

The graphed curves of graph 700 demonstrates that an inductor can have afigure of merit: the Q factor/value based on the Eqn. 1. Here, it isshown that the Q factor can be improved within higher operatingfrequencies than DC current at zero frequency, and be applicable withgreater benefit in the Gigahertz range of operation, such as from24/28/39/60/77 GHz, higher GHz, or lower GHz, especially for mmWaveoperating frequencies.

In particular, the twisting components and the stranded windings with abundle of N strands for a winding (e.g., an inner-most winding,outer-most winding, both inner- and outer-most windings, or windingsin-between or adjacent in a transformer as a primary or secondaryinductor winding) can operate to decrease the detrimental impact of RFproximity effect, which forces the partial currents in the N strands toflow equally distributed.

The advantages for a Quality Factor increase of an inductor ortransformer herein in an RFIC can be applicable to the following withexample advantages: 1) digital controlled oscillator (DCO) CoreInductor: less area, less phase noise, less current spent for LO path,less area consumption for associated LO path, better EVM for receiver(Rx) or transmitter (Tx); 2) a low noise amplifier (LNA) Input MatchInductor: less Area, lower Noise Figure, less current consumption, moreRX selectivity; 3) mmWave Rx/Tx inter-stage coupling transformer: lessarea, less insertion loss, more gain, less number of gain stages needed,less current consumption; or 4) Tx capacitor digital to analog converter(CDAC) Balun: less area, less insertion loss, more available Tx outputpower.

Referring to FIG. 8 , illustrated are example twisting schemes 800 oraspects that can be utilized by one or more twisting components ofvarious aspects herein. The twisting schemes 800 illustrate differenttwisting components 802 thru 806 that can represent differentembodiments of twisting components 406, 414 or otherwise located atdifferent locations along one or more windings of an inductor. Thedotted line represents a connector or joining portion connecting twocuts or spliced strands from the outer-most strand to the inner-moststrand, or vice versa, proximate to one another and offset within alocation of the twisting component, respectively. The other strands canthen be adjusted inward without spanning or hopping over other strandsas with the dotted connect of the twisting component(s).

In particular, at a twist, the innermost strand's path moves to theoutermost strand's former position, the other strands' paths areadjusted towards the center of the inductor. The twisting components orschemes can also applicable for Cases N strands >4. This scheme can alsobe applied for half-windings, or even shorter sections of a winding thatare less than a half or in between a half winding of about 180 degreesand a full winding at 360 degrees.

As also in the example of FIG. 4 , following the path of the innerwinding along 360 degrees of angle, a chosen strand changes its positionin this manner by the applied three twists. This means that under theassumption of a more or less radial-symmetric magnetic field, allstrands are impacted all equally by this electromagnetic field. Thetwisting schemes/components can then also configure an equal currentdistribution among the N strands, and a more effective utilization ofthe available cross-section for conduction of RF currents. Finally, thisresults in lowered Ohmic losses and a higher Quality Factor, compared tothe original design of a solid winding without twisting components orconfigured to a stranded winding of the inductor.

Referring to FIG. 9 , illustrated is an example electromagnetic fielddistribution of the inductor component 400 of FIG. 4 in accord withvarious aspects. An electromagnetic field distribution (Jvol) 900 isillustrated along strands 404 _(1-N) of an inner (or inner-most) winding402, and strands 412 _(1-N) with cross sectional areas associated withcurrent flow along the field gradient. As illustrated, fieldconcentrations with highest current flow can be seen at 212 and 214, andlowest at 232 and 230 with very minimal to no current flow (asnon-conducting areas), for example. Across all strands of both windings402 and 410 a more uniform distribution of current can be seen as afunction of the windings being configured as stranded windings, andtwisting components across various locations along each winding. Thus,an overall increase in the Q factor results. The twisting components andstrands together can enable a substantially equal current distributionamong the plurality of strands of a winding. Additionally, the twistingcomponents and stranded windings increase an effective cross-sectionarea of the first winding available for conduction of radio frequency(RF) currents, in response to the radio frequency integrated circuitoperating in an operating frequency range.

Referring to FIG. 10 , illustrated is another example of an inductor inaccord with various aspects. The inductor component 1000 compriseswindings that can be radially symmetrical along an angular path that issubstantially concentric to one another around a center. The inductorcomponent 100 comprises an outer-most winding 1012 spliced into strands1012 _(1-N) and further configured with two twisting components 1014along different locations coupled to the winding. An inner-most winding1004 is also configured with strands 1004 _(1-N) running parallel alongan angular path of the winding to one another and spaced evenly apartalong the width of the winding. An intermediate or additional winding1024 running about 360 degrees between the outer-most winding 1012 andthe inner-most winding 1004 can also comprise a plurality of N strands(e.g., three) having two (N−1) twisting components 1026 coupled theretoand spanning the strands 1024 _(1-N). Although full windings are shown,as running about 360 degrees around a center point, other windings arealso envisioned that can include additional winding portions runningless than 360 degrees with a full winding.

Terminals 1020 couples to an end of the inner-most winding 1004, whileterminal 1022 couples to another end of the outer-most winding 1012 asan example. However, any number of possible configurations or designscould be envisioned as one of ordinary skill in the art couldappreciate.

Each winding can be spaced further apart than the strands within anyparticular winding as illustrated, for example, but not necessarily.Each group of strands within a winding can be about evenly spaced fromone another and comprise the width of the winding.

Similar to other twisting components described herein, the twistingcomponents 1002, 1014 and 1026 can span the strands within a windingassociated with it as well as be located symmetrically with respect toone another within their associated winding or one another overall. Forexample, at every number of degrees within an angular/radial pathassociated with the winding a twisting component can be coupled to thestrands of the winding. Alternatively, a winding can be asymmetricallylocated along the winding path. The asymmetrical location, for example,can based on an angular field gradient, in which the angular fieldgradient can be associated with an adjacent or surrounding winding.

Each twisting component 1002, 1014 and 1026 can comprise at least twoconnection points 1030 and 1032 at the different locations with aconnector or connecting path 1034 composed of similar or same materialas the winding strands, or a different composition, in which the path1034 joins at an inner-most strand (e.g., at 1030) of the winding to anouter-most strand (e.g., at 1030) of the same winding in order toconnect and twist the two into different positions. The inner-moststrand and the outer-most strand are spliced or cut at the joiningpoints/ends and joined at these connection points 1030 and 1032, forexample. The same aspects apply similarly so to the other twistingcomponents 1002, 1014, and 1026 also. Further, the other strands withinthe location of each twisting component can also be adjusted towardinward positions without interruption or cutting of the strandotherwise.

In one example, the inductor 1000 can comprise a 0.6 nH inductor with anexample operating frequency range of about 3.3 GHz to about 6 GHz. At3.3. GHz the Q factor can be a value of about 12.39, while at 6 GHz beabout 15.4, for example. The width of each winding, whether solid,partially solid, or strand as illustrated can be about 1.8 micrometers“minimum width” and be composed of “thick” copper, while the connectormaterial or strands cross 1034 joining the inner- and outer-most strandswithin a winding at a given location be composed of “thin” copper layer,which is thinner than the thick copper, for example. Other metals couldalso be combined or different for the windings and the cross 1034 orconnector could be of a same thickness or not as the winding. The strandcross/connector 1034 could also connect each strand at a via (not shown)or within an aluminum layer or different metal connection at thestrands, for example.

In another aspect, one or more of the twisting components can furthercomprises the two connection points 1030 and 1032 at the differentlocations for a path twisting the inner-most strand to a position of theouter-most strand, and at least one additional connection point to anextra path there-between or at another point of any one of the strands.

For example, an RF circuitry 1040 can be coupled at the connection areasof connections 1030 and 1032 or elsewhere at the twisting component. TheRF circuitry can include any number of circuit components, coupled inparallel or series, such as a capacitor, another inductor as a secondarycoil, amplifier, or other circuitry without limitation of any onecomponent or device.

In another aspect, rather than a strand crossing 1034 at a twistingcomponent (e.g., 1014), the RF circuitry or any element/componentthereof could join the strands (e.g., from the inner-most strand to theouter-most strand, or otherwise) with or without extra paths (e.g.,capacitor(s), resistor(s), inductor(s), transformer(s), or the like)serving or not as a reactance also forming a weaker connection theretophysically or electromagnetically. In addition, or alternatively, theinductor(s) herein can be formed as one or more primary or secondarywindings with another primary or secondary winding to form a transformeror mutually coupled EMF circuit like a transformer, for example.

Referring to FIG. 11 , illustrated is an example inductor system 1100 inaccord with various aspects. The inductor 1100 comprises similarcomponents as the inductor 1000 of FIG. 10 ; however, the outer-mostwinding 1102 can be a solid metal winding of same, similar, or differentwidth along an angular path as the other windings 1104 and 1024.Although the outer-most winding is solid, it would be stranded and otherwindings 1004, or 1024 be solid without twisting components as well.

The inductor system 1100 further comprises a Q shield 1104, alsoreferred to as a closed-loop guard ring or a closed-loop ground ring,for a monolithic inductor. The Q-shield 1104 can improve isolation tosurrounding or external structures or components, as eddy currents inthe ring can partially cancel emerging field of inductor/transformer.

Referring to FIG. 12 , illustrated is another example inductor system inaccordance with various aspects. The inductor system 1200 is similar as11 of FIG. 11 , but the Q shield is stranded with strands 1202 _(1-N)having twisting components 1204 along the radial path of the Q shield.As a result of the inductor having a more uniform distribution ofcurrent throughout the windings, and increasing the effectivecross-section area of the first winding available for conduction at anoperating frequency range by being stranded and comprising twistingcomponents, the Q shield can also benefit. For example, less materialwould be needed to effect a Q shield or configure it around suchinductor 1100. As such, having a stranded Q shield and twistingcomponents throughout adjacent to or electromagnetically coupled to theinductor can further enable cost and efficiency advantages of an RFIC,for example. As with other twisting components and windings, the numberof N strands can vary in number and is not limited to any particularexample herein, in which N can be an integer of two or more.

Referring to FIG. 13 , illustrated is an example situation forconfiguring a locating scheme for locating or placing twistingcomponents with strands crossings along a particular winding. Forexample, an inductor 1300 is illustrated with a primary inductor 1302 asone winding and a secondary inductor 1304 as another winding, togetherwith an FIG. 8 shape, in which the series windings are not necessarilyplaced concentrically. If the number of strands within any one windingof the inductor 1302 or 1304 (e.g., N=3) is not optimum as the angularelectric field |Hz1| is not equal to |Hz2|, then a correction oflocations along the path of the twisting components can be configured tomaintain or maximize the advantages of having an increase in aneffective cross-section area in a winding that is available forconduction, as well as a substantially equal current distribution acrossstrands of the winding. In particular, as shown in FIG. 13 |Hz1| is notequal to |Hz2| because all along the inner perimeter of the upperwinding 1302 is an angular gradient due to the parallel winding sectionof the other adjacent winding 1304.

Referring to FIG. 14 , illustrated an example locating scheme forlocating or placing twisting components with strands crossings along aparticular winding. An inductor 1400 is illustrated with a primaryinductor 1302 and a secondary inductor 1406 as first and second windingsthat are not necessarily placed concentrically. Instead of havingtwisting components at every 120 degrees, as one embodiment, thetwisting components 1404 can be shifted at an angle more than justadjusting a position as result of a slightly shifted center at eachwinding surrounding an inner winding, as in the FIG. 10 and the windings1002, 1012, 1024, for example.

The twisting components (e.g., two in number for N=3) can be distributedacross the winding to account for or mitigate the effects of an angulargradient detected. The number of twisting components can equal N strandsminus one. Instead of locating a twisting component at a uniform 120degrees from a start point or terminal connection, the twistingcomponents 1404 can be shifted to maximize effect and reduce the angulargradient, or compensate.

In the example of FIG. 14 , the upper winding is stranded and the lowerwinding is solid, but the opposite could also be envisioned, with thelower stranded with twisting components there-along, or both strandedwith twisting components along a winding. Either the upper or lowerwinding, or both could also comprise more than one winding, or a partialwinding according to aspects herein.

While the methods described within this disclosure are illustrated inand described herein as a series of acts or events, it will beappreciated that the illustrated ordering of such acts or events are notto be interpreted in a limiting sense. For example, some acts may occurin different orders and/or concurrently with other acts or events apartfrom those illustrated and/or described herein. In addition, not allillustrated acts may be required to implement one or more aspects orembodiments of the description herein. Further, one or more of the actsdepicted herein may be carried out in one or more separate acts and/orphases.

Referring to FIG. 15 , illustrated is a process flow 1500 for forming aninductor (e.g., a monolithic inductor) of an RFIC as described herein.The method initiates at 1502 with providing a first winding of amonolithic inductor such on an IC board/device in a back end of linesemiconductor fabrication stage.

At 1504, the process flow 1500 further comprising reducing a skin effectof a winding (e.g., a first winding) by splitting the winding into aplurality of strands to increase an effective cross-section area forconduction of radio frequency (RF) currents through the first winding.This can be in response to the radio frequency integrated circuitoperating at an operating frequency range of a Gigahertz frequencyrange, for example.

At 1506, a plurality of twisting components are formed at differentlocations along a radial path of the winding. This can furthercomprising at 1508 cutting, at a location, a first strand of theplurality of strands at a first position along the radial path.

At 1510, the process flow includes cutting a second strand of theplurality of strands at a second position that is proximate to and at anoffset to the first position at the location along the radial path.

At 1512, the process flow can include joining the first strand to thesecond strand at the first position and the second position at thelocation.

In one embodiment, the process flow can also include providing a secondwinding that is substantially radially-symmetric to the first winding;and configuring, via the plurality of twisting components, asubstantially equal current distribution among the plurality of strandsof the first winding.

In another embodiment, the process flow can include any one of theaspects or embodiments discussed herein. For example, forming thetwisting components can include spanning across the first strand and thesecond strand of the plurality of strands, wherein the first strandcomprises an inner-most strand and the second strand comprises anouter-most strand of the plurality of strands.

Other aspects, for example, can also include providing a Q-shield orre-positioning the twisting components based on an angular fieldgradient detected at another winding.

To provide further context for various aspects of the disclosed subjectmatter, FIG. 16 illustrates a block diagram of an embodiment of access(user) equipment related to access of a network (e.g., base station,wireless access point, femtocell access point, and so forth) that canenable and/or exploit features or aspects disclosed herein as related toinductor or transformer configurations and components with strandswithin the windings and twisting components along those strandedwindings.

Access equipment, UE and/or software related to access of a network canreceive and transmit signal(s) from and to wireless devices, wirelessports, wireless routers, etc. through segments 1602 ₁-1602 _(B) (B is apositive integer). Segments 1602 ₁-1602 _(B) can be internal and/orexternal to access equipment and/or software related to access of anetwork, and can be controlled by a monitor component 1604 and anantenna component 1606. Monitor component 1604 and antenna component1606 can couple to communication platform 1608, which can includeelectronic components and associated circuitry that provide forprocessing and manipulation of received signal(s) and other signal(s) tobe transmitted.

In an aspect, communication platform 1608 includes areceiver/transmitter 1610 that can convert analog signals to digitalsignals upon reception of the analog signals, and can convert digitalsignals to analog signals upon transmission. In addition,receiver/transmitter 1610 can divide a single data stream into multiple,parallel data streams, or perform the reciprocal operation. Coupled toreceiver/transmitter 1610 can be a multiplexer/demultiplexer 1612 thatcan facilitate manipulation of signals in time and frequency space.Multiplexer/demultiplexer 1612 can multiplex information (data/trafficand control/signaling) according to various multiplexing schemes such astime division multiplexing, frequency division multiplexing, orthogonalfrequency division multiplexing, code division multiplexing, spacedivision multiplexing. In addition, multiplexer/demultiplexer component1612 can scramble and spread information (e.g., codes, according tosubstantially any code known in the art, such as Hadamard-Walsh codes,Baker codes, Kasami codes, polyphase codes, and so forth).

A modulator/demodulator 1614 is also a part of communication platform1608, and can modulate information according to multiple modulationtechniques, such as frequency modulation, amplitude modulation (e.g.,M-ary quadrature amplitude modulation, with M a positive integer);phase-shift keying; and so forth).

Access equipment and/or software related to access of a network alsoincludes a processor 1616 configured to confer, at least in part,functionality to substantially any electronic component in accessequipment and/or software. In particular, processor 1616 can facilitateconfiguration of access equipment and/or software through, for example,monitor component 1604, antenna component 1606, and one or morecomponents therein. Additionally, access equipment and/or software caninclude display interface 1618, which can display functions that controlfunctionality of access equipment and/or software or reveal operationconditions thereof. In addition, display interface 1618 can include ascreen to convey information to an end user. In an aspect, displayinterface 1618 can be a liquid crystal display, a plasma panel, amonolithic thin-film based electrochromic display, and so on. Moreover,display interface 1618 can include a component (e.g., speaker) thatfacilitates communication of aural indicia, which can also be employedin connection with messages that convey operational instructions to anend user. Display interface 1618 can also facilitate data entry (e.g.,through a linked keypad or through touch gestures), which can causeaccess equipment and/or software to receive external commands (e.g.,restart operation).

Broadband network interface 1620 facilitates connection of accessequipment and/or software to a service provider network (not shown) thatcan include one or more cellular technologies (e.g., third generationpartnership project universal mobile telecommunication system, globalsystem for mobile communication, and so on) through backhaul link(s)(not shown), which enable incoming and outgoing data flow. Broadbandnetwork interface 1620 can be internal or external to access equipmentand/or software and can utilize display interface 1618 for end-userinteraction and status information delivery.

Processor 1616 can be functionally connected to communication platform1608 and can facilitate operations on data (e.g., symbols, bits, orchips) for multiplexing/demultiplexing, such as effecting direct andinverse fast Fourier transforms, selection of modulation rates,selection of data packet formats, inter-packet times, and so on.Moreover, processor 1616 can be functionally connected, through data,system, or an address bus 1622, to display interface 1618 and broadbandnetwork interface 1620, to confer, at least in part, functionality toeach of such components.

Any one or more of the inductors 400-1400 herein can be operably coupledto the processor 1616 or other component as well as to RF circuitry1040. As stated above, RF circuitry 1040 can comprise one or morecircuit elements such as, for example, another inductor to form atransformer. Alternatively, or additionally, the RF circuitry 1040 cancomprise a capacitor as well as any other circuit component (e.g.,resistors, filter, amplifier, transistor, circuitry, etc.) that canfunction to regulate voltage or provide a matching impedance, forexample, with the inductor component(s) or stranded windings withtwistings/twisting components as described herein.

In access equipment and/or software memory 1624 can retain locationand/or coverage area (e.g., macro sector, identifier(s)) access list(s)that authorize access to wireless coverage through access equipmentand/or software sector intelligence that can include ranking of coverageareas in the wireless environment of access equipment and/or software,radio link quality and strength associated therewith, or the like.Memory 1624 also can store data structures, code instructions andprogram modules, system or device information, code sequences forscrambling, spreading and pilot transmission, access pointconfiguration, and so on. Processor 1616 can be coupled (e.g., through amemory bus), to memory 1624 in order to store and retrieve informationused to operate and/or confer functionality to the components, platform,and interface that reside within access equipment and/or software.

As it employed in the subject specification, the term “processor” canrefer to substantially any computing processing unit or deviceincluding, but not limited to including, single-core processors;single-processors with software multithread execution capability;multi-core processors; multi-core processors with software multithreadexecution capability; multi-core processors with hardware multithreadtechnology; parallel platforms; and parallel platforms with distributedshared memory. Additionally, a processor can refer to an integratedcircuit, an application specific integrated circuit, a digital signalprocessor, a field programmable gate array, a programmable logiccontroller, a complex programmable logic device, a discrete gate ortransistor logic, discrete hardware components, or any combinationthereof designed to perform the functions and/or processes describedherein. Processors can exploit nano-scale architectures such as, but notlimited to, molecular and quantum-dot based transistors, switches andgates, in order to optimize space usage or enhance performance of mobiledevices. A processor may also be implemented as a combination ofcomputing processing units.

In the subject specification, terms such as “store,” “data store,” datastorage,” “database,” and substantially any other information storagecomponent relevant to operation and functionality of a component and/orprocess, refer to “memory components,” or entities embodied in a“memory,” or components including the memory. It is noted that thememory components described herein can be either volatile memory ornonvolatile memory, or can include both volatile and nonvolatile memory.

By way of illustration, and not limitation, nonvolatile memory, forexample, can be included in a memory, non-volatile memory (see below),disk storage (see below), and memory storage (see below). Further,nonvolatile memory can be included in read only memory, programmableread only memory, electrically programmable read only memory,electrically erasable programmable read only memory, or flash memory.Volatile memory can include random access memory, which acts as externalcache memory. By way of illustration and not limitation, random accessmemory is available in many forms such as synchronous random accessmemory, dynamic random access memory, synchronous dynamic random accessmemory, double data rate synchronous dynamic random access memory,enhanced synchronous dynamic random access memory, Synchlink dynamicrandom access memory, and direct Rambus random access memory.Additionally, the disclosed memory components of systems or methodsherein are intended to include, without being limited to including,these and any other suitable types of memory.

Examples can include subject matter such as a method, means forperforming acts or blocks of the method, at least one machine-readablemedium including instructions that, when performed by a machine causethe machine to perform acts of the method or of an apparatus or systemfor concurrent communication using multiple communication technologiesaccording to embodiments and examples described herein.

A first example can be an apparatus of a monolithic inductor of a radiofrequency integrated circuit comprising: a first winding comprising aplurality of strands spaced apart from one another with a spacing; asecond winding substantially radially-symmetric to the first winding forgenerating a radially-symmetric magnetic field; and a plurality oftwistings, located at different locations along the first winding,configured to couple to the first winding at the different locations,and span across the plurality of strands of the first winding at thedifferent locations.

A second example includes the subject matter of the first example,wherein a twisting component of the plurality of twistings is configuredto cross-couple a first strand of the plurality of strands with a secondstrand of the plurality of strands at the different locations along thefirst winding.

A third example includes the subject matter of the any one or more ofthe first example thru the second example, wherein the plurality oftwistings is configured to enable a substantially equal currentdistribution among the plurality of strands of the first winding.

A fourth example includes the subject matter of any one or more of thefirst example thru the third example, wherein the plurality of strandsare configured to increase an effective cross-section area of the firstwinding available for conduction of radio frequency (RF) currents, inresponse to the radio frequency integrated circuit operating at afrequency equal to or greater than one Gigahertz.

A fifth example includes the subject matter of any one or more of thefirst example thru the fourth example, wherein the second windingcomprises a solid width that is about equal to a width of the firstwinding.

A sixth example includes the subject matter of any one or more of thefirst example thru the fifth example, wherein the plurality of strandscomprises spacings between pairs of strands that are about equal to oneanother.

A seventh example includes the subject matter of any one or more of thefirst example thru the sixth example, wherein a twisting component ofthe plurality of twistings is configured to increase a Quality (Q)factor of the first winding at an operating frequency range of the radiofrequency integrated circuit.

An eighth example includes the subject matter of any one or more of thefirst example thru the seventh example, wherein a twisting component ofthe plurality of twistings comprises a path that twists an inner-moststrand of the plurality of strands to a position of an outer-most strandof the plurality of strands along the first winding, or the outer-moststrand to a position of the inner-most strand.

A ninth example includes the subject matter of any one or more of thefirst example thru the seventh example, wherein a twisting component ofthe plurality of twistings comprises an adjustment of at least onestrand of the plurality of strands to a different position within thefirst winding extending about parallel between a first strand and asecond strand of the plurality of strands in an angular path.

A tenth example includes the subject matter of any one or more of thefirst example thru the ninth example, wherein the different locationscomprise one less in number along the first winding than the pluralityof strands in the first winding.

A eleventh example includes the subject matter of any one or more of thefirst example thru the tenth example, wherein the plurality of twistingsare asymmetrically spaced, or symmetrically spaced, along an angularpath of the first winding around a center point based on an angularfield gradient.

A twelfth example can be a system of an inductor of a radio frequencyintegrated circuit comprising: a monolithic inductor comprising aplurality of inductor windings, wherein the plurality of inductorwindings comprises at least one first winding and at least one secondwinding, wherein the at least one first winding comprises a number of Nstrands that are split from one another and spaced apart within thefirst winding, wherein N comprises an integer equal to, or greater than,two; and a plurality of twisting components, at different locationsalong the at least one first winding, configured to span across the anumber of N strands of the at least one first inner winding at thedifferent locations.

A thirteenth example includes the subject matter of the twelfth example,wherein inductor windings of the plurality of inductor windings areradially-symmetric to one another to generate a radially-symmetricmagnetic field at an operating frequency range of the radio frequencyintegrated circuit, and comprise a same radial center.

A fourteenth example includes the subject matter of any one or more ofthe twelfth example thru the thirteenth example, further comprising: atransformer comprising the monolithic inductor as a primary inductorwith the plurality of twisting components at the different locations ofthe at least one first winding, and a second monolithic inductor as asecondary inductor arranged substantially concentrically on a plane withrespect to the monolithic inductor and configured to electromagneticallycouple to, or mutually resonate with the primary inductor.

A fifteenth example includes the subject matter of any one or more ofthe twelfth example thru the fourteenth example, further comprising: aQ-shield configured to surround the monolithic inductor and isolate themonolithic inductor with the plurality of twisting components fromoutside interference fields, wherein the Q-shield comprises a solidstrand, or a different plurality of strands with a different pluralityof twisting components at locations along a radial path of the differentplurality of strands.

A sixteenth example includes the subject matter of any one or more ofthe twelfth example thru the fifteenth example, wherein the at least onesecond winding comprises a solid metal winding including a width that isabout equal to a width dimension of the at least one first winding, or aplurality of strands spaced apart from one another along the widthdimension of the at least one second winding.

A seventeenth example includes the subject matter of any one or more ofthe twelfth example thru the sixteenth example, wherein the plurality oftwisting components are configured to cross-couple an inner-most strandof the number of N strands with an outer-most strand of the number of Nstrands at the different locations along the at least one first winding,wherein the different locations comprise symmetrical, or asymmetricalpositions, with respect to one another along a radial path of the atleast one first winding based on an angular field gradient at the atleast one second winding.

An eighteenth example includes the subject matter of any one or more ofthe twelfth example thru the seventeenth example, wherein the pluralityof twisting components further comprises at least two connection pointsat the different locations for a path twisting the inner-most strand toa position of the outer-most strand, and at least one additionalconnection point to an extra path.

A nineteenth example includes the subject matter of any one or more ofthe twelfth example thru the eighteenth example, further comprising oneor more winding crossings coupling one or more strands of the number ofN strands between the inner-most strand and the outer-most strand of theat least one first winding with strands of the at least one secondwinding, wherein the one or more winding crossing comprise less strandsthan the number of N strands.

A twentieth example can be a method of forming a monolithic inductor fora radio frequency integrated circuit comprising: providing a firstwinding of the monolithic inductor; reducing a skin effect of the firstwinding by splitting the first winding into a plurality of strands toincrease an effective cross-section area available for conduction ofradio frequency (RF) currents through the first winding, in response tothe radio frequency integrated circuit operating at an operatingfrequency range of a Gigahertz frequency range; forming a plurality oftwistings at different locations along a radial path of the firstwinding comprising: cutting, at a location, a first strand of theplurality of strands at a first position along the radial path; cuttinga second strand of the plurality of strands at a second position that isproximate to and at an offset to the first position at the locationalong the radial path; and joining the first strand to the second strandat the first position and the second position at the location.

A twenty-first example includes the subject matter of the twentiethexample, further comprising: providing a second winding that issubstantially radially-symmetric to the first winding; and configuring,via the plurality of twistings, a substantially equal currentdistribution among the plurality of strands of the first winding.

A twenty-second example includes the subject matter of any one or moreof the twentieth example thru the twenty-first example, furthercomprising: spanning, at the plurality of twistings, across the firststrand and the second strand of the plurality of strands, wherein thefirst strand comprises an inner-most strand and the second strandcomprises an outer-most strand of the plurality of strands.

A twenty-third example can be an apparatus of a monolithic inductor of aradio frequency integrated circuit comprising: a winding comprising aplurality of strands split and spaced apart from one another within awinding path comprising a winding width, wherein the winding pathextends radially as an angular path at least three hundred and sixtydegrees around a center point, wherein the plurality of strands areconfigured to increase an effective cross-section area of the windingavailable for conduction of radio frequency (RF) currents in response tothe radio frequency integrated circuit operating within a Gigahertzfrequency range; and a plurality of twistings located at differentlocations along the winding located at different locations along thewinding, configured to couple to the winding at the different locations,and span across the plurality of strands of the winding at the differentlocations.

A twenty-fourth example includes the subject matter of the twenty-thirdexample, further comprising: a second winding substantiallyradially-symmetric to and adjacent the winding for generating aradially-symmetric magnetic field; wherein the plurality of twistingsare configured to enable a substantially equal current distributionamong the plurality of strands of the winding.

A twenty-fifth example includes the subject matter of any one or more ofthe twenty-third example thru the twenty-fourth example, furthercomprising: a transformer comprising the monolithic inductor as aprimary inductor with the plurality of twistings at the differentlocations of the winding, and a second monolithic inductor as asecondary inductor arranged substantially concentrically on a plane withrespect to the monolithic inductor and configured to electromagneticallycouple to, or mutually resonate with the primary inductor, wherein thesecond monolithic inductor comprises the second winding or at least onethird winding.

Examples can include one or more non-transitory computer-readable mediacomprising instructions to cause an electronic device, upon execution ofthe instructions by one or more processors of the electronic device, toperform one or more elements of a method described in or related to anyof examples above, or any other method or process described herein.

Examples can include an apparatus comprising logic, modules, orcircuitry to perform one or more elements of a method described in orrelated to any of examples above, or any other method or processdescribed herein.

Examples can include a method, technique, or process as described in orrelated to any of examples above, or portions or parts thereof.

Examples can include an apparatus comprising: one or more processors andone or more computer readable media comprising instructions that, whenexecuted by the one or more processors, cause the one or more processorsto perform the method, techniques, or process as described in or relatedto any of examples above, or portions thereof.

Examples can include a method of communicating in a wireless network asshown and described herein.

Examples can include a system for providing wireless communication asshown and described herein.

Examples can include a device for providing wireless communication asshown and described herein.

It is to be understood that aspects described herein can be implementedby hardware, software, firmware, or any combination thereof. Whenimplemented in software, functions can be stored on or transmitted overas one or more instructions or code on a computer-readable medium.Computer-readable media includes both computer storage media andcommunication media including any medium that facilitates transfer of acomputer program from one place to another. A storage media or acomputer readable storage device can be any available media that can beaccessed by a general purpose or special purpose computer. By way ofexample, and not limitation, such computer-readable media can compriseRAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic diskstorage or other magnetic storage devices, or other tangible and/ornon-transitory medium, that can be used to carry or store desiredinformation or executable instructions. Also, any connection is properlytermed a computer-readable medium. For example, if software istransmitted from a website, server, or other remote source using acoaxial cable, fiber optic cable, twisted pair, digital subscriber line(DSL), or wireless technologies such as infrared, radio, and microwave,then coaxial cable, fiber optic cable, twisted pair, DSL, or wirelesstechnologies such as infrared, radio, and microwave are included in thedefinition of medium. Disk and disc, as used herein, includes compactdisc (CD), laser disc, optical disc, digital versatile disc (DVD),floppy disk and blu-ray disc where disks usually reproduce datamagnetically, while discs reproduce data optically with lasers.Combinations of the above should also be included within the scope ofcomputer-readable media.

Various illustrative logics, logical blocks, modules, and circuitsdescribed in connection with aspects disclosed herein can be implementedor performed with a general purpose processor, a digital signalprocessor (DSP), an application specific integrated circuit (ASIC), afield programmable gate array (FPGA) or other programmable logic device,discrete gate or transistor logic, discrete hardware components, or anycombination thereof designed to perform functions described herein. Ageneral-purpose processor can be a microprocessor, but, in thealternative, processor can be any conventional processor, controller,microcontroller, or state machine. A processor can also be implementedas a combination of computing devices, for example, a combination of aDSP and a microprocessor, a plurality of microprocessors, one or moremicroprocessors in conjunction with a DSP core, or any other suchconfiguration. Additionally, at least one processor can comprise one ormore modules operable to perform one or more of the s and/or actionsdescribed herein.

For a software implementation, techniques described herein can beimplemented with modules (e.g., procedures, functions, and so on) thatperform functions described herein. Software codes can be stored inmemory units and executed by processors. Memory unit can be implementedwithin processor or external to processor, in which case memory unit canbe communicatively coupled to processor through various means as isknown in the art. Further, at least one processor can include one ormore modules operable to perform functions described herein.

Techniques described herein can be used for various wirelesscommunication systems such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA and othersystems. The terms “system” and “network” are often usedinterchangeably. A CDMA system can implement a radio technology such asUniversal Terrestrial Radio Access (UTRA), CDMA1800, etc. UTRA includesWideband-CDMA (W-CDMA) and other variants of CDMA. Further, CDMA1800covers IS-1800, IS-95 and IS-856 standards. A TDMA system can implementa radio technology such as Global System for Mobile Communications(GSM). An OFDMA system can implement a radio technology such as EvolvedUTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE802.16 (WiMAX), IEEE 802.18, Flash-OFDM□, etc. UTRA and E-UTRA are partof Universal Mobile Telecommunication System (UMTS). 3GPP Long TermEvolution (LTE) is a release of UMTS that uses E-UTRA, which employsOFDMA on downlink and SC-FDMA on uplink. UTRA, E-UTRA, UMTS, LTE and GSMare described in documents from an organization named “3rd GenerationPartnership Project” (3GPP). Additionally, CDMA1800 and UMB aredescribed in documents from an organization named “3rd GenerationPartnership Project 2” (3GPP2). Further, such wireless communicationsystems can additionally include peer-to-peer (e.g., mobile-to-mobile)ad hoc network systems often using unpaired unlicensed spectrums, 802.xxwireless LAN, BLUETOOTH and any other short- or long-range, wirelesscommunication techniques.

Single carrier frequency division multiple access (SC-FDMA), whichutilizes single carrier modulation and frequency domain equalization isa technique that can be utilized with the disclosed aspects. SC-FDMA hassimilar performance and essentially a similar overall complexity asthose of OFDMA system. SC-FDMA signal has lower peak-to-average powerratio (PAPR) because of its inherent single carrier structure. SC-FDMAcan be utilized in uplink communications where lower PAPR can benefit amobile terminal in terms of transmit power efficiency.

Moreover, various aspects or features described herein can beimplemented as a method, apparatus, or article of manufacture usingstandard programming and/or engineering techniques. The term “article ofmanufacture” as used herein is intended to encompass a computer programaccessible from any computer-readable device, carrier, or media. Forexample, computer-readable media can include but are not limited tomagnetic storage devices (e.g., hard disk, floppy disk, magnetic strips,etc.), optical disks (e.g., compact disk (CD), digital versatile disk(DVD), etc.), smart cards, and flash memory devices (e.g., EPROM, card,stick, key drive, etc.). Additionally, various storage media describedherein can represent one or more devices and/or other machine-readablemedia for storing information. The term “machine-readable medium” caninclude, without being limited to, wireless channels and various othermedia capable of storing, containing, and/or carrying instruction(s)and/or data. Additionally, a computer program product can include acomputer readable medium having one or more instructions or codesoperable to cause a computer to perform functions described herein.

Communications media embody computer-readable instructions, datastructures, program modules or other structured or unstructured data ina data signal such as a modulated data signal, e.g., a carrier wave orother transport mechanism, and includes any information delivery ortransport media. The term “modulated data signal” or signals refers to asignal that has one or more of its characteristics set or changed insuch a manner as to encode information in one or more signals. By way ofexample, and not limitation, communication media include wired media,such as a wired network or direct-wired connection, and wireless mediasuch as acoustic, RF, infrared and other wireless media.

Further, the actions of a method or algorithm described in connectionwith aspects disclosed herein can be embodied directly in hardware, in asoftware module executed by a processor, or a combination thereof. Asoftware module can reside in RAM memory, flash memory, ROM memory,EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, aCD-ROM, or any other form of storage medium known in the art. Anexemplary storage medium can be coupled to processor, such thatprocessor can read information from, and write information to, storagemedium. In the alternative, storage medium can be integral to processor.Further, in some aspects, processor and storage medium can reside in anASIC. Additionally, ASIC can reside in a user terminal. In thealternative, processor and storage medium can reside as discretecomponents in a user terminal. Additionally, in some aspects, the actsand/or actions of a method or algorithm can reside as one or anycombination or set of codes and/or instructions on a machine-readablemedium and/or computer readable medium, which can be incorporated into acomputer program product.

The above description of illustrated embodiments of the subjectdisclosure, including what is described in the Abstract, is not intendedto be exhaustive or to limit the disclosed embodiments to the preciseforms disclosed. While specific embodiments and examples are describedherein for illustrative purposes, various modifications are possiblethat are considered within the scope of such embodiments and examples,as those skilled in the relevant art can recognize.

In this regard, while the disclosed subject matter has been described inconnection with various embodiments and corresponding Figures, whereapplicable, it is to be understood that other similar embodiments can beused or modifications and additions can be made to the describedembodiments for performing the same, similar, alternative, or substitutefunction of the disclosed subject matter without deviating therefrom.Therefore, the disclosed subject matter should not be limited to anysingle embodiment described herein, but rather should be construed inbreadth and scope in accordance with the appended claims below.

In particular regard to the various functions performed by the abovedescribed components (assemblies, devices, circuits, systems, etc.), theterms (including a reference to a “means”) used to describe suchcomponents are intended to correspond, unless otherwise indicated, toany component or structure which performs the specified function of thedescribed component (e.g., that is functionally equivalent), even thoughnot structurally equivalent to the disclosed structure which performsthe function in the herein illustrated exemplary implementations of thedisclosure. In addition, while a particular feature may have beendisclosed with respect to only one of several implementations, suchfeature may be combined with one or more other features of the otherimplementations as may be desired and advantageous for any given orparticular application.

The invention claimed is:
 1. An apparatus of a monolithic inductor of aradio frequency integrated circuit comprising: a primary inductor as afirst winding comprising at least three strands spaced apart from oneanother with a predetermined spacing; a secondary inductor as a secondwinding substantially radially-symmetric to the first winding forgenerating a radially-symmetric magnetic field; a plurality oftwistings, located at different locations along the first winding,configured to couple to the first winding at the different locations,and span across the at least three strands of the first winding at thedifferent locations; wherein a twisting of the plurality of twistingscomprises a path that twists an inner-most strand of the at least threestrands to a position of an outer-most strand of the at least threestrands along the first winding, or the outer-most strand to a positionof the inner-most strand; wherein the first winding and the secondwinding form a shape of an eight.
 2. The apparatus of claim 1, wherein atwisting of the plurality of twistings is configured to cross-couple afirst strand of the at least three strands with a second strand of theat least three strands at the different locations along the firstwinding.
 3. The apparatus of claim 1, wherein the plurality of twistingsis configured to enable a substantially equal current distribution amongthe at least three strands of the first winding.
 4. The apparatus ofclaim 1, wherein the at least three strands are configured to increasean effective cross-section area of the first winding available forconduction of radio frequency (RF) currents, in response to the radiofrequency integrated circuit operating at a frequency equal to orgreater than one Gigahertz.
 5. The apparatus of claim 1, wherein thesecond winding comprises a solid width that is about equal to a width ofthe first winding.
 6. The apparatus of claim 1, wherein a first portionof the second winding comprises a solid width that is about equal to awidth of the first winding; and wherein a second portion of the secondwinding comprises a plurality of twistings, located at differentlocations along the second portion of the second winding, configured tocouple to the second winding at the different locations, and span acrossthe at least three strands of the second portion of the second windingat the different locations; wherein a twisting of the plurality oftwistings comprises a path that twists an inner-most strand of the atleast three strands to a position of an outer-most strand of the atleast three strands along the second portion of the second winding, orthe outer-most strand to a position of the inner-most strand.
 7. Theapparatus of claim 1, wherein the at least three strands comprisesspacings between pairs of strands that are about equal to one another.8. The apparatus of claim 1, wherein a twisting of the plurality oftwistings is configured to increase a Quality (Q) factor of the firstwinding at an operating frequency range of the radio frequencyintegrated circuit.
 9. The apparatus of claim 1, wherein a twisting ofthe plurality of twistings comprises an adjustment of at least onestrand of the at least three strands to a different position within thefirst winding extending about parallel between a first strand and asecond strand of the at least three strands in an angular path.
 10. Theapparatus of claim 1, wherein the different locations comprise at leastone less in number along the first winding than the at least threestrands in the first winding.
 11. The apparatus of claim 1, wherein theplurality of twistings are asymmetrically spaced, or symmetricallyspaced, along an angular path of the first winding around a center pointbased on an angular field gradient.
 12. The apparatus of claim 1,wherein a strand of the at least three strands has a width which is aminimum width according to the integrated circuit fabrication processspecification or technology.
 13. A system of an inductor of a radiofrequency integrated circuit comprising: a monolithic inductorcomprising a plurality of inductor windings, wherein the plurality ofinductor windings comprises at least one first winding and at least onesecond winding, wherein the at least one first winding comprises anumber of N strands that are split from one another and spaced apartwithin the first winding, wherein N comprises an integer equal to, orgreater than, three; a plurality of twisting components as twistings, atdifferent locations along the at least one first winding, configured tospan across the a number of N strands of the at least one first innerwinding at the different locations; wherein the plurality of twistingcomponents are configured to cross-couple an inner-most strand of thenumber of N strands with an outer-most strand of the number of N strandsat the different locations along the at least one first winding, whereinthe different locations comprise symmetrical, or asymmetrical positions,with respect to one another along a radial path of the at least onefirst winding based on an angular field gradient at the at least onesecond winding.
 14. The system of claim 13, wherein inductor windings ofthe plurality of inductor windings are radially-symmetric to one anotherto generate a radially-symmetric magnetic field at an operatingfrequency range of the radio frequency integrated circuit, and comprisea same radial center.
 15. The system of claim 13, further comprising: atransformer comprising the monolithic inductor as a primary inductorwith the plurality of twisting components at the different locations ofthe at least one first winding, and a second monolithic inductor as asecondary inductor arranged substantially concentrically on a plane withrespect to the monolithic inductor and configured to electromagneticallycouple to, or mutually resonate with the primary inductor.
 16. Thesystem of claim 13, further comprising: a Q-shield configured tosurround the monolithic inductor and isolate the monolithic inductorwith the plurality of twisting components from outside interferencefields, wherein the Q-shield comprises a solid strand, or a differentplurality of strands with a different plurality of twisting componentsat locations along a radial path of the different plurality of strands.17. The system of claim 13, wherein the at least one second windingcomprises a solid metal winding including a width that is about equal toa width dimension of the at least one first winding, or a plurality ofstrands spaced apart from one another along the width dimension of theat least one second winding.
 18. The system of claim 13, wherein a firstportion of the at least one second winding comprises a solid width thatis about equal to a width of the at least one first winding; and whereina second portion of the at least one second winding comprises aplurality of twistings, located at different locations along the secondportion of the at least one second winding, configured to couple to theat least one second winding at the different locations, and span acrossthe plurality of strands of the second portion of the at least onesecond winding at the different locations; wherein a twisting of theplurality of twistings comprises a path that twists an inner-most strandof the plurality of strands to a position of an outer-most strand of theplurality of strands along the second portion of the at least one secondwinding, or the outer-most strand to a position of the inner-moststrand.
 19. The system of claim 13, wherein the plurality of twistingcomponents further comprises at least two connection points at thedifferent locations for a path twisting the inner-most strand to aposition of the outer-most strand, and at least one additionalconnection point to an extra path.
 20. The system of claim 13, furthercomprising: one or more winding crossings coupling one or more strandsof the number of N strands between the inner-most strand and theouter-most strand of the at least one first winding with strands of theat least one second winding, wherein the one or more winding crossingcomprise less strands than the number of N strands.
 21. The system ofclaim 13, wherein one or more strands of the number of N strands have awidth which is a minimum width according to the integrated circuitfabrication process specification or technology.
 22. An apparatus of amonolithic inductor of a radio frequency integrated circuit comprising:a winding comprising a at least three strands split and spaced apartfrom one another within a winding path comprising a winding width,wherein the winding path extends radially as an angular path at leastthree hundred and sixty degrees around a center point, wherein the atleast three strands are configured to increase an effectivecross-section area of the winding available for conduction of radiofrequency (RF) currents in response to the radio frequency integratedcircuit operating within a Gigahertz frequency range; a plurality oftwistings located at different locations along the winding located atdifferent locations along the winding, configured to couple to thewinding at the different locations, and span across the at least threestrands of the winding at the different locations; wherein a twisting ofthe plurality of twistings comprises a path that twists an inner-moststrand of the at least three strands to a position of an outer-moststrand of the at least three strands along the winding, or theouter-most strand to a position of the inner-most strand.
 23. Theapparatus of claim 22, further comprising: a second windingsubstantially radially-symmetric to and adjacent the winding forgenerating a radially-symmetric magnetic field; wherein the plurality oftwistings are configured to enable a substantially equal currentdistribution among the at least three strands of the winding.
 24. Theapparatus of claim 23, further comprising: a transformer comprising themonolithic inductor as a primary inductor with the plurality oftwistings at the different locations of the winding, and a secondmonolithic inductor as a secondary inductor arranged substantiallyconcentrically on a plane with respect to the monolithic inductor andconfigured to electromagnetically couple to, or mutually resonate withthe primary inductor, wherein the second monolithic inductor comprisesthe second winding or at least one third winding.
 25. The apparatus ofclaim 22, wherein a strand of the at least three strands has a widthwhich is a minimum width according to the integrated circuit fabricationprocess specification or technology.